The films of the present invention are particularly adapted and useful in bags used for consumer self-packaging applications such as are common in the produce sections of supermarkets. Some of the properties desired of these films are as follows: puncture resistance, tear resistance and tensile strength in the transverse and machine directions, contact clarity, low haze, high gloss, the ability to produce the film in thin gauges, low specific gravity and thus high yield in area per pound, tensile toughness, and high modulus of elasticity. Of particular importance in the present application are film strength and clarity. Overall film strength is desirable so that the films may be employed with confidence in a number of different applications. Film clarity is desirable for two reasons. First, a clear film enables the user to easily see exactly what is inside the bag without opening the bag. Second, a clear film bolsters loss prevention efforts by supermarkets because the check-out clerks are able to view the contents of the bag and do not need to rely on the statements of the consumer or spend time inspecting the bag themselves.
A particular film is selected for an end use because of the particular properties it possesses and the film may have some properties which are desirable and others which are less so. For example, while a pure high molecular weight high density polyethylene (HMW HDPE) film has superior strength, toughness and puncture resistance, it has significant shortcomings with respect to gloss, haze and contact clarity. Metallocene-catalyzed polyethylene, while having superior gloss, haze and contact clarity, has only moderate tensile strength and significant cost limitations.
A need exists for films which have superior optical characteristics as well as excellent strength and puncture resistance. Such films could be used in a wider variety of end applications.